LOS ANGELES/NEW YORK, Aug 31 (Reuters) - The “Guardians of the Galaxy” misfits reached a new box office stratosphere over the U.S. Labor Day weekend, soaring past fellow Marvel hero “Captain America” to become the highest-grossing domestic movie of 2014.

“Guardians” rung up $16.3 million in U.S. and Canadian ticket sales from Friday through Sunday, topping weekend charts for the third time since its Aug. 1 debut, according to estimates from tracking firm Rentrak. Total domestic sales climbed to $274.6 million, surpassing the $259.8 million earned by April release, “Captain America: The Winter Soldier.”

The offbeat “Guardians” stars Chris Pratt and Zoe Saldana as leaders of a group of warriors that includes a talking raccoon and a human-like tree.

“Teenage Mutant Ninja Turtles,” a reboot of the franchise born in 1980s comic books, ranked second with $11.8 million domestically from Friday through Sunday.

“If I Stay,” starring Chloe Grace Moretz as a girl who has an out-of-body experience after a catastrophic car accident, took the No. 3 spot with $9.3 million.

Low-budget horror flick “As Above, So Below” debuted in fourth, collecting an estimated $8.3 million. The movie follows a team of explorers as they venture through the Paris catacombs.